I think these sentences are uncorrect，「after」 is a kind of proposition，which can't be connected with the sentence 「I get home」 or 「I'm getting home」.The correct form in my opinion should be this one:「After getting home,i will eat dinner」. Have you copied it?If you have any problems,please contact me anytime.I'm especially interested in Japanese language,Would you like to become my precious language learning partner and friend？

You should say, "After I get home, I will eat dinner". Or "When I get home, I will eat dinner". Your arrival home is at a definite time. It is not continuous.